1. Field of the Invention
The present invention relates generally to transformers, and, more particularly, to a transformer for use on a winning machine utilized in underground mining.
2. Description of the Prior Art
Winning operations which involve long wall mining procedures typically utilize electrically powered drum cutter mining machines. The drum cutter mining machine, also referred to as a shearer loader, is positioned proximate to a mine wall, whereat a mineral is sheared from the mine wall face. The drum cutter mining machine includes at least one, and usually two, circular cutting drums extending from opposite ends of the mining machine. A first cutting drum, the leading cutting drum extends at an upwardly projecting angle from the drum cutter mining machine. The second cutting drum, the trailing cutting drum, extends at a downwardly extending angle from the drum cutter mining machine. Three-phase electrical motors cause the cutting drums to rotate, in either the clockwise or counter-clockwise directions, depending upon the direction of the drum cutter mining machine. During cutting operations, the leading cutting drum shears a first portion of the mine wall, and the trailing cutting drum shears a second portion of the mine wall.
Because a limited amount of space is available in the mine, a primary design consideration when designing the mining machine is to minimize the dimensions of non-cutting portions of the machine. Transformers must be positioned on the mining machine in order to provide the cutting drum motors with electrical power of suitable characteristics. Because of the above-mentioned size limitations, efforts have been made to limit the size of the transformers.
Design considerations additionally require the inclusion of coolant systems to prevent overheating of the transformer. Still further, the design of the transformer must be such that the transformer may be quickly and simply dismantled and reassembled.
It is therefore the object of the present invention to provide an improved transformer for an underground mining machine of minimum dimensions.